Ok, this one has probably been asked a lot. I got an Olympus 600L and it does 1280x1024. Now, I want to print on the Alps md1300 which does 1200x600 dpi max. The big question is, will be the effect of the quality of the picture especially on 8x10 prints. I just can never figure that out? Will I see any difference? I kept hearing people talk about this 200dpi is all you need on a dye sublim and anything higher than is wasted. What is that all about? By the way, which is the best program to print photo and get the best printed results?

Simon

Simon

-- simon lim (simon_lim@ins.com), August 14, 1998

Answers

200dpi is about all there is in a conventional C print. At 8x10, a D600L gives you 128dpi to work with (no tricks there, just simple division). This rule just lets you speculate about the quality of the resulting print as compared to an enlargement of a good negative.

The resolution of the output device is mostly irrelevant, except as it measures the limits of the quality of its output. Huge numbers like 1200x600 come from halftone devices which can only make each dot one of 4 or 9 colors. They require a lot more dots to reproduce a subtle tone than a dye-sub printer which can just make each dot exactly the right color.

If you're printing under windows, the program you use is also largely irrelevant, because the important work will be done by the printer driver, which will be the same for any program you use. Personally I use Lview on the rare occasion that I print from windows.

Print quality is highly subjective anyway -- just try printing an 8x10 and if you like it, great! I can assure you that a D600L *is* capable of taking an image that looks great at 8x10 (I have three on the wall next to me). If you like the image when displayed on a 17" monitor, remember that there are printers out there which can make hardcopy which looks just as good.

-- Ben Jackson (ben@ben.com), August 16, 1998.

To get reasonable detail in a halftone print, the resolution or pixel count should idealy be 1.3 times the required halftone LPI. For a 133 LPI line screen image, the supplied image should be at least 133 x 1.3 = 173 pixels per inch. This may not be enough to show fine detail but is often good enough for what it is used. Some unsharp masking in the halftone stage may make this image look better. A safer system would be to interpolate an image to a higher DPI in applications like Photoshop but additional sharpening is still required during halftone scanning or conversion. So if all is as said, a 1800 x 1200 Pixel image can (without cropping or interpolating) produce a halftone image of 1800 : 1.3 = 1383 LPI and 1200 : 1.3 = 923 or 1383x923 LPI (halftone dots) In the printing stage this can make a halftone of 10.4" x 6.94" This is a reasonable expectation if no other processing steps are used. Never use a JPEG file for print work because the JPEG artifacts are, if not visible in small detail, a real pain in large smooth areas that start to look like "paint by number" sections. According to Agfa and (ePhoto1680 with PhotoGenie) interpolating with some types of software can easily increase the resolution of your file without detriment. Detail is always limited by pixel size but a well lit (!!!!!!!) digital picture makes a better halftone then a poor silver print. Rinus Borgsteede

-- Rinus Borgsteede (RinusPhoto@cadvision.com), June 22, 1999.